Ce对Zn-Al-Mg合金镀层组织和耐腐蚀性能的影响  

Effect of Ce on the Microstructure and Corrosion Resistance of Zn-Al-Mg Alloy Coatings

作　　者：蒋红兵 李强 徐巍 田银宝 冀璞光 陶文明 方峰[2] JIANG Hongbing;LI Qiang;XU Wei;TIAN Yinbao;JI Puguang;TAO Wenming;FANG Feng(Jiangsu Yasheng Metal Products Co.,Ltd.,Taizhou 225700,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]江苏亚盛金属制品有限公司,江苏泰州225700 [2]东南大学材料科学与工程学院,江苏南京211189

出　　处：《材料保护》2024年第1期14-20,共7页Materials Protection

基　　金：国家自然科学基金资助项目(52171110);江苏省先进金属材料高技术重点实验室课题(AMM2020A02)。

摘　　要：为了考察Ce含量对热浸镀Zn-Al-Mg合金镀层的组织和耐腐蚀性能的影响,采用SEM、EDS、XRD等方法对镀层的形貌、组织成分及物相进行了观察分析,结合盐雾试验对腐蚀产物形貌、组成及含量以及去除腐蚀产物后的镀层形貌进行了分析,并进一步通过电化学测试考察了不同镀层在3.5%NaCl溶液中的电化学行为。结果表明,Zn-5Al-1.5Mg-xCe (x=0, 0.05, 0.10, 0.25,质量分数,%)合金镀层的组织由富Zn相、富Al相和Zn/Al/MgZn_(2)(或Mg_(2)Zn_(11))三元共晶组织组成,少量Ce的加入增加了镀层中三元共晶组织的比例。Ce可以减薄镀层,细化富Al相,提高镀层的均匀性。当Ce添加量为0.10%时,细化效果最好。另外,Zn-5Al-1.5Mg-0.10Ce合金镀层的耐腐蚀性能最好,是Zn-5Al-1.5Mg合金镀层的2.6倍左右。Ce提高了镀层的均匀性,减少了局部腐蚀,提高了Zn_5(OH)_8Cl_(2)·H_(2)O腐蚀产物保护层的均匀性和致密性,从而提高了镀层的耐腐蚀性能。For investigating the effect of Ce content on the structure and corrosion resistance of hot-dip Zn-Al-Mg alloy coatings, SEM, EDS, XRD and other methods were used to observe and analyze the morphology, structural composition and physical phase of the coating. Combined with the salt spray test, the morphology, composition and content of the corrosion products and the morphology of the coating after removing the corrosion products were analyzed, and the electrochemical behavior of different coatings in 3.5% NaCl solution was further evaluated through electrochemical tests. Results showed that the microstructure of Zn-5Al-1.5Mg-xCe(x=0, 0.05, 0.10, 0.25, mass fraction, the same below) alloy coating was composed of Zn-rich phase, Al-rich phase and Zn/Al/MgZn_(2)(or Mg_(2)Zn_(11)) ternary eutectic structure. The small addition of Ce could increase the proportion of the ternary eutectic structure of the coating. Furthermore, Ce could thin the plating layer, refine the Al-rich phase, and improve the uniformity of the plating layer. When the dosage of Ce was 0.10%, the refinement effect was the best. In addition, the corrosion resistance of Zn-5Al-1.5Mg-0.10Ce alloy coating was the best, which was about 2.6 times that of Zn-5Al-1.5Mg alloy coating. Overall, Ce promoted the uniformity of the coating, reduced local corrosion, improved the uniformity and compactness of the protective layer of Zn_5(OH)_8Cl_(2)·H_(2)O corrosion products, and thus enhanced the corrosion resistance of the coating.

关 键 词：Zn-Al-Mg-Ce合金镀层 Ce含量 耐腐蚀性能 微观组织 

分 类 号：TU511.2[建筑科学—建筑技术科学] TB37[一般工业技术—材料科学与工程]